music |
 | | OSdata.com |
Assembly Language
data conversion
summary
This web page examines data conversion instructions in assembly language. Specific examples of instructions from various processors are used to illustrate the general nature of assembly language.
free computer programming text book project
If you like the idea of this project,
then please donate some money.
more information on donating |
Now building a For those with high speed connections, the very large single file summary is still on line.
For information on how to interface high level languages and assembly languages, seeassembly/high level language interface
data conversion
Data conversion instructions change data from one format to another.
A sign extension operation takes a small value and sign extends it to a larger storage format (such as byte to word).
A type conversion operation changes data from one format to another (such as signed two’s complement integer into binary coded decimal).
- EXT Sign Extend; Motorola 680x0, Motorola 68300; sign extends a byte (8 bits) in a data register to a word (16 bits) or sign extends a word (16 bits) in a data register to a longword (32 bits); sets or clears flags
- CVT Convert; DEC VAX; converts a signed quantity to a different signed data type, source and destination in register or memory, special rounded versions for certain floating conversions; sets or clears flags
- CVTBW Convert Byte to Word; sign extend
- CVTBL Convert Byte to Long; sign extend
- CVTWB Convert Word to Byte; truncated
- CVTWL Convert Word to Long; sign extend
- CVTLB Convert Long to Byte; truncated
- CVTLW Convert Long to Word; truncated
- CVTBF Convert Byte to Floating; exact
- CVTBD Convert Byte to Double float; exact
- CVTWF Convert Word to Floating; exact
- CVTWD Convert Word to Double float; exact
- CVTLF Convert Long to Floating; rounded
- CVTLD Convert Long to Double float; exact
- CVTFB Convert Floating to Byte; truncated
- CVTDB Convert Double float to Byte; truncated
- CVTFW Convert Floating to Word; truncated
- CVTDW Convert Double float to Word; truncated
- CVTFL Convert Floating to Long; truncated
- CVTRFL Convert Rounded Floating to Long; rounded
- CVTDL Convert Double float to Long; truncated
- CVTRDL Convert Rounded Double float to Long; rounded
- CVTFD Convert Floating to Double float; exact
- CVTDF Convert Double float to Floating; rounded
- CBW Convert Byte to Word; Intel 80x86; sign extends a byte (8 bits) in register AL to create a word (16 bits) in the AX register; does not affect flags
- CWD Convert Word to Doubleword; Intel 80x86; sign extends a word (16 bits) in register AX throughout the DX register to create a doubleword (32 bits); does not affect flags
- CWDE Convert Word to Doubleword Extended; Intel 80386; sign extends a word (16 bits) in register AX to create a doubleword (32 bits) in the EAX register; does not affect flags
- CDQ Convert Doubleword to Quadword; Intel 80386; sign extends a doubleword (32 bits) in register EAX to create a quadword (64 bits) in the EDX register; does not affect flags
- EXTB Sign Extend Byte; Motorola 680x0, Motorola 68300; sign extends a byte (8 bits) in a data register to a longword (32 bits); sets or clears flags
- MOVSX Move with Sign Extension; Intel 80x86; moves data from a register or memory to a register, with a sign extension (conversion to larger binary integer: byte to word, byte to doubleword, or word to doubleword); does not affect flags
- MOVZX Move with Zero Extension; Intel 80x86; moves data from a register or memory to a register, with a zero extension (conversion to larger binary integer: byte to word, byte to doubleword, or word to doubleword); does not affect flags
- MOVZ Move Zero Extended; DEC VAX; converts an unsigned integer to a larger unsigned integer, source and destination in register or memory (MOVZBW Byte to Word, MOVZBL Byte to Long, MOVZWL Word to Long); sets or clears flags
- NUM Convert to Numeric; MIX; converts byte encoded character code (MIX character code) in A-register/X-register pair to numeric data in the A-register (accumulator), does not change sign, overflow possible
- CHAR Convert to Characters; MIX; converts numeric data in the A-register (accumulator) into byte encoded character code (MIX character code) in A-register/X-register pair, does not change signs
- PACK Pack; Motorola 680x0; converts byte encoded numeric data (such as ASCII or EBCDIC characters) into binary coded decimals using an adjustment field ($3030 for ASCII, $F0F0 for EBCDIC), either from data register to data register or memory location to memory location with predecrement of address pointers; does not modify flags
- UNPK Unpack; Motorola 680x0; converts binary coded decimals into byte encoded numeric data (such as ASCII or EBCDIC characters) using an adjustment field ($3030 for ASCII, $F0F0 for EBCDIC), either from data register to data register or memory location to memory location with predecrement of address pointers; does not modify flags
Now building a For those with high speed connections, the very large single file summary is still on line.
free music player coding example
Programming example: I am making heavily documented and explained open source PHP/MySQL code for a method to play music for free — almost any song, no subscription fees, no download costs, no advertisements, all completely legal. This is done by building a front-end to YouTube (which checks the copyright permissions for you).
View music player in action: www.musicinpublic.com/.
Create your own copy from the original source code/ (presented for learning programming). Includes how to run this from your own computer if you don’t have a web site.
return to table of contents
free downloadable college text book
Because I no longer have the computer and software to make PDFs, the book is available as an HTML file, which you can convert into a PDF.
A web site on dozens of operating systems simply can’t be maintained by one person. This is a cooperative effort. If you spot an error in fact, grammar, syntax, or spelling, or a broken link, or have additional information, commentary, or constructive criticism, please e-mail Milo. If you have any extra copies of docs, manuals, or other materials that can assist in accuracy and completeness, please send them to Milo, PO Box 1361, Tustin, CA, USA, 92781.
Click here for our privacy policy.
two levels up
special topics
one level up
peer level
free computer programming text book project
Building a free downloadable text book on computer programming for university, college, community college, and high school classes in computer programming.
If you like the idea of this project,
then please donate some money.
send donations to:
Milo
PO Box 1361
Tustin, California 92781
Supporting the entire project:
If you have a business or organization that can support the entire cost of this project, please contact Pr Ntr Kmt (my church)
more information on donating
Some or all of the material on this web page appears in the
free downloadable college text book on computer programming. |
I do the news as an unpaid volunteer for KOCI 101.5 FM, Newport Beach/Costa Mesa (also available on the web)
This web site handcrafted on Macintosh 
computers using Tom Bender’s Tex-Edit Plus 
and served using FreeBSD 
.
Names and logos of various OSs are trademarks of their respective owners.
Copyright © 2000, 2001 Milo
Created: February 21, 2001 (from machcode.htm)
Last Updated: February 21, 2001
return to table of contents
free downloadable college text book
